Dog ownership, and therefore also dog breeding, is on the rise. This means it is more important than ever to make sure that we are breeding and buying our wonderful canine companions responsibly and with respect to their health. There are now a huge variety of tests available to give us more information about our dogs’ genetic make-up and health. It is excellent to have so much choice. But it can also be very confusing to decide what tests, if any, you should be investigating. Read on to find out more!
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What types of genetic testing can you do?
There are a whole host of tests you can run on any sort of dog, depending on what kind of information you are looking for.
DNA testing
DNA (or deoxyribonucleic acid, if you’re feeling scientific), is the structure that makes up our dog’s entire self. Genes determine both physical characteristics such as coat colour and size. But also their temperament, activity levels and their likes and dislikes.
DNA testing can look through your dog’s genetic code to find a multitude of answers. The tests are simple and non-invasive to perform; usually with a cheek swab, which you can do at home, or occasionally a small blood sample performed by a vet.
1) Breed
If you have a crossbreed, you may think you know their parentage, but some crosses can be more mixed than you might think! If you have a true Heinz 57, it can be really interesting to use genetic testing to find out what breeds make up your pooch. You may be surprised by the answers!
2) Inherited disease
There are many diseases which show a strong genetic link, with some breeds being much more at risk of developing them than others. Genetic disease testing can be used in two ways; either to assess if your dog is at higher risk of developing certain diseases, or to see if they are suitable for breeding. By only breeding dogs with low risk of a breed-related disease, these genetic health traits should slowly diminish.
There is a massive list of genetically carried diseases that we can test for. This includes retinal atrophy, dwarfism and exercise-induced collapse. The Kennel Club has more information on which breeds are predisposed to which conditions. You can test for a specific disease, or pick a breed ‘bundle’, which tests for all the genetic conditions that the breed has known links to.
Testing for other hereditary diseases
There are some health conditions with a strong genetic link that cannot be tested for using DNA from a cheek swab or blood. But they are still important genetically, especially for breeding purposes.
1) Hip and elbow scoring
Hip and elbow dysplasia are hereditary joint diseases where there is malformation of the joint which can lead to mobility problems including early arthritis. These conditions are particularly common in large-breed dogs such as the German Shepherd, Labrador and Golden Retrievers. The scoring involves x-rays being taken of the joints under sedation or anaesthetic. These are then sent to a panel of experts to examine and give a score to. This score can then be compared to a breed average. This is to see if breeding from the dog would negatively or positively affect the prevalence of joint dysplasia in the breed.
2) Eye testing
There are various eye conditions that are hereditary and passed down through the gene pool. It is therefore important if you are considering breeding that you check that your dog doesn’t have any eye conditions that might pass on to their offspring. These eye exams are done by specialists, and may include some breed-specific tests.
3) Breathing function
Breeds with brachycephalic faces (squashed face breeds such as pugs and bulldogs) are hugely prone to respiratory difficulties. BOAS (Brachycephalic Obstructive Airway Syndrome) is an inherited condition where the poor conformation of these dogs’ airways results in blocked airways and reduced airflow. Breeding dogs should be assessed as to whether their offspring are likely to suffer respiratory difficulties.
4) Deafness testing
There are some breeds, such as the Dalmatian, White Boxer and Australian Shepherd, who are more likely to be affected by congenital deafness, when they are born completely deaf. BAER (Brainstem Auditory Evoked Response) is a test involving the brainstem’s response to noise that can assess this.
Interpreting the tests
Some tests will be very easily understood. Such as those looking at which breeds make up your beloved mixed breed pet.
Some tests are a bit more tricky. If your dog tests positive for an inherited disease, it does not mean that they will definitely get that disease. Likewise, if they test negative, it is no guarantee that they will 100% never develop it. Genetic tests must be interpreted with care: they are a guide to health and probability only. For most conditions, a positive, or high scoring, test means your dog is more likely to develop the genetic condition than a dog who tests negative (or gains a low score). But there are a lot of other genes and environmental factors to tie into the big picture.
If you own a breed that is prone to certain health conditions, genetic testing can be useful to know how much monitoring should be put in place. If you’re considering breeding, it is best to breed from dogs who are either free from problematic genes which can code for specific illnesses. Or who are above the breed standard. So their offspring and future generations should be working towards making the breed healthier and less prone to disease. Dog owners, breeders and health professionals all want the same outcome; healthier and happier dogs of all breeds, shapes and sizes.
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